The U.S. Marine Corps is preparing to move forward with a potential procurement of specialized 5.56x45mm anti-drone ammunition designed to turn standard-issue rifles into close-range counter-uncrewed aerial system (c-sUAS) weapons, according to a recent acquisition notice. The effort reflects a growing urgency across U.S. forces to equip even individual infantry Marines with tools capable of engaging small, fast, and increasingly lethal drones on modern battlefields.
According to a notice published by the Marine Corps Systems Command (MARCORSYSCOM), the service intends to issue a sole-source contract for the acquisition of an unspecified quantity of 5.56x45mm “L Variant” cartridges produced by Drone Round. The projected award date is December 2026, though officials have not disclosed how quickly the rounds could be fielded or in what quantities.
The ammunition is designed for use in standard Marine rifles such as the M4 carbine, M4A1, and M27 Infantry Automatic Rifle without modification.
In a justification accompanying the notice, MARCORSYSCOM argued that Drone Round’s L Variant represents the only currently available option meeting the Marine Corps’ minimum requirements for immediate counter-small UAS defense.
“The 5.56mm Drone Round ‘L Variant’ is the only kinetic munition currently available in the commercial or defense marketplace that meets the Marine Corps’ strict minimum capability requirements for immediate c-sUAS defense,” the document states, emphasizing its “drop-in” compatibility with existing weapons systems.
The justification stresses that the ammunition requires no weapon modifications, specialized training pipelines, or changes to Marine Corps occupational specialties. “Failure to deliver this capability places an unnecessary risk to Marines and could lead to mission failure and loss of life,” it adds, underscoring the perceived urgency of fielding the technology as drone threats proliferate across global conflict zones.
Drone Round has been developing specialized small-arms anti-drone ammunition since at least 2025. The company currently produces two primary 5.56x45mm variants: the L Variant and a more aggressive K Variant.
Both cartridges use projectiles designed to break apart after leaving the barrel, dispersing into multiple sub-projectiles. The L Variant splits into five fragments, while the K Variant divides into eight. The intent is to increase the likelihood of striking small aerial targets such as first-person view (FPV) kamikaze drones, which have become a defining feature of the war in Ukraine.
According to Drone Round, the L Variant is effective out to approximately 100 meters (328 feet), while the shorter-range K Variant is optimized for engagements around 50 meters (164 feet). Both are designed for use in semi-automatic and fully automatic fire and are reportedly suppressor-compatible.
While the company has focused primarily on 5.56x45mm ammunition, it has also developed 7.62x51mm variants, with 6.8x51mm versions under development for compatibility with newer U.S. Army systems such as the M7 rifle and associated next-generation weapons family.
Marine Corps interest in “enhanced ammunition” is not new. As early as 2024, MARCORSYSCOM listed buckshot-like or multi-projectile cartridges as part of its desired suite of squad-level counter-drone capabilities. The broader vision is to ensure that every Marine—regardless of specialty—can contribute to counter-UAS defense at the tactical edge.
Marine Corps officials have repeatedly emphasized this distributed approach. Speaking at the Navy League’s Sea-Air-Space conference, Marine Col. Paul Gilikin, Program Manager for Combat Support Systems at MARCORSYSCOM, noted that the service is actively seeking industry support for ammunition solutions tailored to existing weapons systems.
“For our ammunition portfolio, we need industry’s help in counter-UAS munitions for our existing weapon systems,” Gilikin said, highlighting the emphasis on simplicity, compatibility, and immediate usability under combat conditions.
The concept behind fragmenting or multi-projectile rifle ammunition is not new. The U.S. Army explored similar ideas in the 1950s and 1960s, testing various “shotgun-like” rifle rounds intended to increase hit probability against moving targets. None were ultimately adopted at scale, largely due to ballistic trade-offs and limited battlefield applicability at the time.
Commercial analogues also exist. The well-known Glaser Safety Slug, for example, used pre-fragmented projectiles intended for close-range defensive use. However, these designs were generally optimized for law enforcement or personal defense scenarios rather than battlefield anti-air applications.
What is new is the explicit adaptation of these concepts for counter-drone warfare. The rapid proliferation of inexpensive, disposable drones—especially FPV loitering munitions—has revived interest in increasing “volume of fire” per trigger pull to compensate for the difficulty of tracking and hitting small aerial targets.
The Marine Corps is not alone in exploring such concepts. The Naval Surface Warfare Center, Crane Division (NSWC Crane) has previously developed its own internal “Drone Killer Cartridge” (DKC) designs in 5.56x45mm, 7.62x51mm, and .50 caliber configurations.
In controlled demonstrations, the DKC reportedly achieved a 92% success rate against drone targets, according to Navy statements. However, it remains unclear how mature the program is or whether it has transitioned beyond experimental testing.
The U.S. Army has also evaluated similar ammunition concepts, including Drone Round’s L Variant, according to reports. Some assessments have reportedly extended to partner forces, including Ukrainian units actively engaged in high-intensity drone warfare.
The war in Ukraine has become a proving ground for anti-drone innovations of all kinds. Both Ukrainian and Russian forces have experimented with specialized small-arms ammunition designed to increase hit probability against FPV drones.
In some cases, improvised solutions include 3D-printed sabots loaded with steel BBs or other dispersing payloads. More formalized production has also emerged from established defense manufacturers, including the Kalashnikov Concern, which has developed its own counter-drone ammunition concepts.
The Ukrainian Armed Forces have similarly integrated a mix of shotguns, modified rifle rounds, and electronic countermeasures into their layered air defense approach. These developments have influenced procurement discussions in NATO countries, including the United States.
Anti-drone ammunition is also being paired with advanced fire-control optics designed to improve hit probability against fast-moving aerial targets. Systems such as the SMASH family developed by Smart Shooter are already in limited use across U.S. and allied forces.
These systems use computer vision to track and compute firing solutions for small, maneuvering targets. In some experimental setups, Marines have also tested rifle-mounted systems that physically assist aiming by adjusting weapon alignment to match target movement.
Analysts suggest that pairing such optics with fragmenting ammunition could significantly improve effectiveness at short range, though software integration and ballistic modeling would likely require refinement.
Supporters of multi-projectile 5.56mm ammunition argue that it addresses a key problem in counter-drone engagements: the difficulty of achieving a direct hit on small, rapidly moving targets with a single projectile. By dispersing multiple fragments, each trigger pull theoretically increases the probability of at least one impact.
However, the concept is not without limitations. Effective range is significantly reduced compared to standard rifle ammunition. Drone Round’s L Variant, for example, is cited as effective to roughly 100 meters, while a standard M4 carbine can engage point targets at distances approaching 500 meters under optimal conditions.
This creates a tactical trade space: soldiers gain increased short-range anti-drone capability but sacrifice long-range precision if ammunition management becomes mixed or confused in combat.
There are also doctrinal concerns. Counter-drone engagements often occur at extremely short notice, where soldiers may have only seconds to react. Some analysts argue that standing and firing may increase exposure, as static shooters become easier targets for drone operators.
A Russian counter-drone training manual reportedly notes that engaging drones with small arms can make the shooter easier to target, since firing requires remaining stationary. Whether movement-based tactics or suppression fire will dominate future doctrine remains unresolved.
Shotguns remain one of the most widely adopted kinetic counter-drone tools globally due to their inherent spread pattern, which mirrors the logic behind fragmenting rifle ammunition. They are widely used in Ukraine, particularly for last-ditch defense against FPV drones.
However, their effective range is typically limited to very short distances, often below 50 meters. Fragmenting rifle rounds aim to extend that envelope while maintaining compatibility with standard infantry weapons.
Still, experts caution that no single solution is sufficient. Counter-drone defense increasingly relies on layered systems combining electronic warfare, kinetic interceptors, directed-energy weapons, and small-arms solutions as a final line of defense.
The Marine Corps’ interest in Drone Round’s L Variant reflects a broader shift in modern infantry warfare: the normalization of aerial threats at the lowest tactical level. What were once niche or specialized countermeasures are now being considered baseline infantry capabilities.
